1. Producing acetate may help bifidobacteria protect the human gut from infection, suggests a paper in Nature this week. Bifidobacteria, sometimes used by the food industry as probiotics, are natural inhabitants of the human gut where they help protect against infection. However, their mode of action is unclear. Hiroshi Ohno and colleagues show that certain features of bifidobacterial metabolism that ultimately lead to the production of acetate are involved in this effect.

1. Lightning Rod for Head and Neck Cancer - They say lightning never strikes the same place twice—unless of course, that place is a lightning rod. An enzyme called UROD acts like a lightning rod for cancer cells, drawing radiation and chemotherapy toward specific spots in diseased tissue, a new study in mice and humans reports. The findings suggest that UROD—identified for the first time in this paper as a key player in human cancer--could help decrease treatment side effects for people with head and neck cancer, the eighth most common cancer worldwide. Despite many advances over the last few decades, the toxic side effects associated with current therapies have made for disappointing outcomes in many patients. Head and neck tumors are often found near critical organs, so destroying the diseased tissue is often a delicate challenge that could lead to life-threatening conditions.

2. New Drug Slows Down Graft-Versus-Host Disease - A new drug slows down the progression of graft-versus-host disease by targeting immune cells' metabolism, reports a new study in mice. If this compound works in humans the way it does in mice, it will be a completely different kind of treatment for patients with graft-versus-host disease or GVHD, a common condition that occurs after transplants when donor immune cells begin to attack the recipient's body. Currently, the only treatment available involves high-dose steroids, which only work for half of all patients and come with serious side effects

1. To Infants, Might Makes Right: Even babies understand that being brawny comes in handy during a conflict, new research suggests. Scientists have learned that young children appear to be naturally empathetic and helpful, which is certainly heartwarming, but group living also entails conflicting goals and competition for scarce resources. In this study, Lotte Thomsen and colleagues investigated whether young children also have mental representations of social dominance that could help them function in hierarchial cultures. In particular, the researchers looked at body size, which is a nearly universal indicator of social rank across the animal kingdom. They showed infants a video in which two cartoon squares with faces (abstract enough to distill just the relevant information about size and conflict) first block each other's path and then one bows down to the other and moves away. The researchers measured the amount of time the babies spent watching variations of the cartoon. This time interval is generally understood to reflect whether the babies find a scene is expected or surprising. The results showed that 10- to 13-month-olds, but not eight-month-olds, use size as a cue to predict which agent will win the contest. It thus appears that we learn some of the basic rules of social hierarchies at a very young age.

2. Cancer Drug May Help Heal Spinal Injuries: The administration of the cancer drug Taxol to rats with spinal injuries reduced scarring and removed some of the barriers that normally prevent axons – the long, slender projections of nerve cells – from regenerating, researchers say. Thus, it appears that treatment with Taxol could stimulate the capacity of damaged axons to grow after spinal cord injuries. Farida Hellal and colleagues report these findings and explain that scarring as well as the intrinsic nature of axons, which refuse to grow back after injury, are both controlled by the dynamics of microtubules, which are components of the cytoskeleton. The Taxol drug, which has been deemed an effective cancer treatment over the years, acts on these microtubules. According to the researchers, Taxol's effect on the injured rodents' cytoskeleton helped to stabilize their microtubules through a variety of cellular processes. Consequently, Hellal and colleagues observed a reduction of scarring in the rats along with the enhanced capacity of axons to grow back. In the future, they say Taxol might be combined with other therapies to treat spinal injuries in humans as well.

3. A Uniquely Warm Arctic Inflow: The water flowing from the Atlantic Ocean into the Arctic through the Fram Strait, which cuts between Greenland and Svalbard, is warmer today than any time in the past 2,000 years, according to a new report. Researchers suggest that this unprecedented warm water is a key player in the present, ongoing transition to an ice-free Arctic Ocean. Because historical measurements only reach back about 150 years, Robert Spielhagen and colleagues sampled marine sediments off the coast of Western Svalbard – an archipelagic region of Norway – and made a record of oceanic temperature variations over the last two millennia. Their sampling site was strategically positioned in the path of warm, Atlantic water inflow to the Arctic Ocean, and fossils of ancient planktonic foraminifer contained within the sediment cores informed the researchers' data sets. The Arctic region of our planet has been responding more rapidly to global warming than most other areas, and the researchers suggest that their findings are a sign of human activities speeding this process along.

1. New findings show how bacteria undergo genome evolution - Scientists at the Institut Pasteur and the University of Maryland have revealed how bacterial and archaea microbes successfully evolve their gene repertoires to face new challenges, predominantly by acquiring genes from other individuals. The study, published in the open-access journal PLoS Genetics on Jan. 27, was instigated to clarify the role of gene duplication, an important source of novelty in multicellular organisms, in bacteria.

2. Celiac disease and Crohn's disease share part of their genetic background An investigation has found that celiac disease and Crohn's disease, both inflammatory diseases of the gastrointestinal tract, share at least four genetic risk loci. International researchers performed a combined meta-analysis of genome-wide data for celiac disease and Crohn's disease. This meta-analysis, published in the open-access journal PLoS Genetics on Jan. 27, has identified two new shared risk loci and two shared risk loci that had previously been independently identified for each disease.

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